This classic text reads as well now as it did 15 years ago when I read it as graduate student. Should be accessible to better undergraduates but everyone interested in mathematics can take pleasure in this presentation of a wide variety of topics in basic Fourier theory together with interesting applications. But note that this book is not an introduction to current research in harmonic analysis. For that one should look at books by Stein and others. Nonetheless, this is a beautiful introduction the basic theory.
